Comparison of ultrasonographic and morphological findings of paravertebral muscles at the apex of kyphoscoliosis in patients with neurofibromatosis type I

Background With the extensive research literature on kyphoscoliosis diagnostic criteria remain clinical in patients with neurofibromatosis type I. Paraspinal muscles have been under-evaluated in the cohort of patients. Objective To compare ultrasonographic and morphological measurements of paraspinal muscles at the apex of kyphoscoliosis in patients with neurofibromatosis type I. Material and methods The study included 10 patients who underwent surgical correction of spine deformity. Ultrasound measurements of paraspinal muscles were produced preoperatively. Muscle biopsy specimen was obtained intraoperatively at the apex of the deformity and histologically evaluated with optical microscope. Results Ultrasonographic examination of paraspinal muscles showed typical hypertrophy at the kyphosis site, bilaterally impaired striation and high acoustic impedance in patients with neurofibromatosis. Morphological evaluation revealed fibrosis of endomysium and perimysium, extensive areas of fibrosis and adipocytes replacing muscular fibres that translated into a great number of hyperechogenic hypertrophic bundles of fibres on ultrasonographic images. Conclusion Ultrasonographic findings of paraspinal muscles (hypertrophy, impaired muscle striation, high acoustic impedance) are on par with pathomorphological manifestations (revealed fibrosis of endomysium and perimysium, extensive areas of fibrosis and adipocytes replacing muscular fibres). The findings indicate to degeneration of muscle tissue with malfunction to follow. Ultrasound imaging allows for examination of paraspinal muscles, measuring thickness of superficial and deep muscles, acoustic impedance to identify fibrous changes and replacement of muscles by adipose tissue.